Objective To compare the effects of crown lengthening and gingivectomy in the restoration of residual roots, crowns and posts. Methods From 2006 to 2008, 50 patients (58 teeth) were randomly divided into two groups according to the order of admission. Gingivectomy (30 teeth) and crown lengthening (28 teeth) were used to completely expose the cross section, and conventional post-crown restoration was performed 6 weeks later. The curative effect and periodontal health status of the two groups were evaluated 2 weeks after post-crown restoration. Results Two weeks after operation, the total effective rate was 96.67%(29/30) in the crown lengthening group and 765,438 0.43% (20/28) in the gingivectomy group, the difference was statistically significant (P